If you can pull that off, not only will you have nailed the career and the state with the highest percentages of 65-plus workers, you will be smack in the middle of a demographic trend with some troubling implications.

It's evidence, according to the Wall Street Journal, of the near impossibility of saving enough for retirement in a bad economy after two stock market crashes. Further, says WSJ, senior workers remaining in the workforce with no corresponding job creation in the economy actually increase unemployment.

South Dakota's rate of 65-plus workforce participation, 5.9 percent, is highest in the country. Florida is number five on that list with 5.5 percent. The data show the national percentage of senior workers has been growing since 2008, even as the total workforce shrank.

Here's a list of the top occupations for workers over 65, along with a participation rate for each. Click to the Careerbuilder site for a list of careers in which practitioners are aging fastest.